tectorigenin and Prostatic-Neoplasms

In this study, an efficient strategy based on bioassay-guided fractionation, high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q/TOF-MS) and high-speed counter-current chromatography (HSCCC) was established to screen and purify bioactive compounds from Chinese herbal medicines (CHMs). This screening system was efficient and successfully applied to reveal anti-prostate cancer candidates from Puerariae thomsonii Flos. As a result, an active fraction with strong in vitro anti-prostate cancer activity was obtained, and the main compounds in the fraction were purified by HSCCC, giving 82 mg of tectoridin, 36 mg of tectorigenin-7-O-[β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside and 64 mg of tectorigenin. Among them, tectorigenin, possessing the highest anti-prostate cancer activity with IC₅₀ value of 0.08 μM, has priority to be lead compound. The results of this work demonstrated that the developed method was efficient and could be employed for the rapid screening, identification and purification of active components from CHMs.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Chromatography, High Pressure Liquid; Countercurrent Distribution; Drug Discovery; Drug Screening Assays, Antitumor; Drugs, Chinese Herbal; Ethnopharmacology; Glycosides; Inhibitory Concentration 50; Isoflavones; Male; Mice; Molecular Structure; Prostatic Neoplasms; Pueraria; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

In the prostate, estrogen receptor beta (ERbeta), the preferred receptor for phytoestrogens, has features of a tumor suppressor. To investigate the mechanisms underlying the beneficial effects on prostate cancer of histone deacetylase inhibitor valproic acid (VPA) and phytoestrogen tectorigenin, we analyzed the expression of ERbeta after tectorigenin or VPA treatment. For further functional analysis, we knocked down ERbeta expression by RNA interference. LNCaP prostate cancer cells were treated with 5 mmol/L VPA or 100 micromol/L tectorigenin and transfected with small interfering RNA (siRNA) against ERbeta. Control transfections were done with luciferase (LUC) siRNA. Expression of ERbeta was assessed by Western blot. mRNA expression was quantitated by real-time reverse transcription-PCR. Expression of ERbeta mRNA and protein markedly increased after VPA or tectorigenin treatment. When ERbeta was knocked down by siRNA, the expression of prostate-derived Ets factor, prostate-specific antigen, prostate cancer-specific indicator gene DD3(PCA3), insulin-like growth factor-1 receptor, the catalytic subunit of the telomerase, and ERalpha was up-regulated and the tectorigenin effects were abrogated. ERbeta levels were diminished in prostate cancer and loss of ERbeta was associated with proliferation. Here, we show that siRNA-mediated knockdown of ERbeta increases the expression of genes highly relevant to tumor cell proliferation. In addition, we show that one prominent result of treatment with VPA or tectorigenin is the up-regulation of ERbeta resulting in antiproliferative effects. Thus, these drugs, by restoring the regulatory function of ERbeta in tumor cells, could become useful in the intervention of prostate cancer.

Topics: Blotting, Western; Cell Proliferation; Cell Survival; Enzyme Inhibitors; Estrogen Receptor beta; Histone Deacetylase Inhibitors; Humans; Isoflavones; Male; Phytoestrogens; Prostatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Tumor Cells, Cultured; Valproic Acid

Phytoestrogenes are plant-derived compounds that have been shown to exert an antiproliferative potential on prostate cancer cells, although the exact mechanisms are still unclear. In prostate cancer cells proliferation is regulated by modulation of the IGF-1 receptor (IGF-R-1) by the androgen receptor (AR) and its co-activator prostate derived Ets factor (PDEF). Phytooestrogenes interact with these mechanisms as demonstrated exemplarily in the presented study with the isoflavone tectorigenin derived from Belamcanda chinensis.. Cultured androgen-sensitive LNCaP prostate cancer cells were treated with tectorigenin of 100 microM for 24 hours. The mRNA-expression of AR, PSA, PDEF, hTERT, TIMP-3 and IGF-R-1 were quantified by real-time RT-PCR. Furthermore, the expression or activity of PSA, telomerase and IGF-R-1 was measured on the protein level. In addition, we investigated in nude mice the influence of a diet of extracts of Belamcanda chinensis on the growth of subcutaneously injected LNCaP cells versus a control group of animals fed with a soy-free diet.. In cultured LNCaP cells treatment with tectorigenin resulted in a significant down-regulation of the gene expression of AR, PDEF, PSA, IGF-R-1 and hTERT. On the protein level PSA secretion and the activity of telomerase and IGF-R-1 expression was also decreased. The gene expression of TIMP-3 was distinctly up-regulated by tectorigenin. Nude mice fed with Belamcanda chinensis extract showed a significantly decreased incidence and tumor growth compared to controls.. Tectorigenin shows an inhibition of the IGF-1-R modulated cell proliferation of PCa-Cells, due to modulation of the activity the co-activator PDEF independently from the AR. Furthermore, tectorigenin has pro-apoptotic effects and decreases tissue invasion by up-regulation of TIMP-3. Therefore, phytooestrogenes are an interesting option in the therapy of prostate especially advanced prostate cancer.

Topics: Animals; Antineoplastic Agents; Biomarkers, Tumor; Cell Line, Tumor; Cell Survival; Feasibility Studies; Humans; Isoflavones; Male; Mice; Mice, Nude; Neoplasm Proteins; Phytoestrogens; Phytotherapy; Plant Extracts; Prostatic Neoplasms; Treatment Outcome

Isoflavones have been shown to exert antiproliferative effects on cancer cells by steroid receptor signaling. In this study, we demonstrate the potential of plant constituents extracted from Belamcanda chinensis as anticancer drugs, which regulate the aberrant expression of genes relevant in proliferation, invasion, immortalization and apoptosis. LNCaP cells were treated with B.chinensis extract, tectorigenin or other isoflavones and mRNA expression was quantified by using real time RT-PCR. In addition, ELISA, TRAP assays and western blots were used to measure protein expression or activity. Male nude mice (n=18) were injected subcutaneously with LNCaP cells and were fed with extracts from B.chinensis, and tumor development was monitored versus a control animal group (n=18). Tectorigenin and several other phytochemicals downregulated PDEF, PSA and IGF-1 receptor mRNA expression in vitro. Furthermore, PSA secretion and IGF-1 receptor protein expression were diminished, and hTERT mRNA expression and telomerase activity decreased after tectorigenin treatments. However, TIMP-3 mRNA was upregulated on tectorigenin treatment. Growth of subcutaneous tumors in nude mice was delayed and diminished in animals fed with extracts from B.chinensis. The downregulation of PDEF, PSA, hTERT and IGF-1 receptor gene expression by tectorigenin demonstrates the antiproliferative potential of these agents. The upregulation of TIMP-3 gene expression indicates a pro-apoptotic function of the drug and a reduction of the invasiveness of tumors. The animal experiments demonstrate that B.chinensis markedly inhibited the development of tumors in vivo. Thus, these compounds may be useful for the prevention or treatment of human prostate cancer.

Topics: Animals; Base Sequence; Biomarkers, Tumor; Cell Division; Cell Line, Tumor; DNA Primers; Humans; Isoflavones; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Phytotherapy; Plant Extracts; Polymerase Chain Reaction; Prostatic Neoplasms; Transplantation, Heterologous

Phytoestrogens are nonsteroidal plant derived compounds with estrogenic activity that have been implicated in protecting against prostate cancer progression. We hypothesized that these compounds would alter cell number and increase the ability of antiandrogens to induce cell death in prostate cancer cells.. RWPE-1, LNCaP and PC-3 cells were treated with or without an extract of Belamcanda chinensis, 2 purified phytoestrogens derived from this extract (irigenin and tectorigenin) and the antiandrogen bicalutamide. We assessed the effect on cell number, proliferation and apoptosis.. Phytoestrogens (50 to 100 microM) and bicalutamide (10 to 50 microM) alone decreased the cell number in all 3 cell lines. Phytoestrogens (50 microM) combined with bicalutamide (10 microM) further decreased the number of RWPE-1 and PC-3 cells compared to these agents alone. Tectorigenin and irigenin inhibited the proliferation of RWPE-1, LNCaP and PC-3 cells, causing G1 arrest and the induction of p21WAF1 or p27 protein expression, whereas bicalutamide induced apoptosis in a dose dependent manner in all 3 cell lines. Phytoestrogens did not have antiandrogenic activity.. These in vitro studies demonstrate a role for tectorigenin and irigenin in regulating prostate cancer cell number by inhibiting proliferation through cell cycle regulation.

Topics: Cell Division; Cell Line, Tumor; Drug Evaluation, Preclinical; Humans; Iridaceae; Isoflavones; Male; Phytoestrogens; Plant Extracts; Prostatic Neoplasms; Tumor Cells, Cultured